Abstract
We identified one unique kind of anatomical characteristics of thoracic duct (TD) in four cases using fluorescence thoracoscopy during right lung cancer surgery. In these patients, a collateral branch was gave off from TD at the level of the azygos vein arch, which ran along the superior edge of the azygos vein arch, moving from posterior to anterior, and then turned upward in the anterior mediastinum with complex branching patterns. The branches can be easily injured during surgery, which could lead to postoperative chylothorax.